DENVER -- Cardinals shortstop Aledmys Díaz's stellar rookie season hit a bit of a speed bump in his return from the disabled list prior to Monday's series opener against the Rockies. Manager Mike Matheny noticed something was off with Diaz's throws from short and figured he could use a day off as Diaz continues to recover from a fractured right thumb.
"When you have surgery on your throwing hand, you can do arm strengthening exercises, but you can't replicate the throwing itself," Matheny said. "It takes time, just like a pitcher -- you got to build up. The same thing goes with being a position player, having to have your arm in throwing shape. To do it day in, day out, that's really [what the trainers] are keeping their eye on more than anything else, much more so than the hand."
Diaz missed all of August and the first 11 days of this month due to the thumb injury he sustained on July 31. Since returning, Diaz has hit a pair of big home runs, one in his first start against the Cubs on Sept. 13 and the other on Sunday against the Giants. He's 4-for-23 overall since his return, giving Diaz a .303 average on the season (114-for-376) with 16 homers and 26 doubles.
"He did what most players do when they make a splash in this league," Matheny said. "They kick the door in when they get the opportunity. There was no looking back."
Diaz has played 103 games through Monday, 18 more than in any season but last season, when he played 116 games between Double-A Springfield and Triple-A Memphis.

"We kind of knew we were going to have to keep an eye on him," Matheny said. "Once again, trust the trainers when something doesn't look right. His body is just trying to get into the everyday playing shape. He's another kid that has never played this late in the year. All that put together, we're going to have to take advantage of the days when they tell us we need to."
Matheny gave Diaz a similar break on Thursday and was happy with the results.
"Last time we did that, he came back right away," Matheny said. "He got a little treatment, a few extra things he could do when he didn't have to get ready for the game, and he was significantly better."
Diaz is eager to keep contributing in the home stretch of the postseason race, but Matheny is comfortable exercising some short-term restraint for the long-term good.
"He wants to push right now, because he knows, he hears, he sees exactly what's going on," Matheny said. "But you can tell it was going to be one of those days, and the trainers verified that once they ran through some tests."
Matheny is also taking Coors Field into consideration, knowing the toll the altitude and the offensive quality of the games can take on a team. The Cardinals took batting practice inside in the hitting cages on Tuesday to help preserve energy for the game.
"If we can take a little bit off our guys, maybe not having them go out and run around quite as much, if we save a little bit, it's worth it," Matheny said.